The invention relates to a method and a system for the ultrasonic testing of a test object.
For the nondestructive testing of test objects, a very wide variety of ultrasonic test methods are known. For better localization and separation of the defects during nondestructive testing with ultrasound, the SAFT (Synthetic Aperture Focusing Technique) analysis technique is known. The inspection is in this case carried out like a conventional ultrasonic test, but the data are recorded without rectification. During the subsequent analysis of the measurement data, amplitude sums are determined from a multiplicity of measurement signals for respective small volume elements, which are also referred to as so-called voxels. Ultrasonic testing with the aid of SAFT analysis is conventionally used in the case of automated movement of a test head emitting the ultrasound pulses and receiving the corresponding echo signals.
By the use of so-called phased-array test heads, test objects can be scanned not only mechanically but also electronically, i.e. a plurality of measurements are carried out in a defined grid by a kind of electronic displacement of the test head. In the case of a stationary test head, data that have been recorded with the same electronic scan can be evaluated by SAFT analysis. This works both for an unmoved test head and for a test head moved during the electronic scan, when the exact emission and reception positions and incidence angle and focusing at the reconstruction time are known.